JPH02299791A - Workpiece irradiating method with laser beam - Google Patents

Abstract

PURPOSE:To easily irradiate a workpiece at a narrower irradiation point interval with a laser beam from one laser beam oscillator by splitting the laser beam into >=2 by a conical lens and controlling an apex angle of the conical lens at the time of condensing the laser beams by a condenser lens. CONSTITUTION:The workpiece is irradiated with the laser beam 5 from the laser beam oscillator 1 and the central axis of the conical lens 3 is brought in line with the central axis of the laser beam 5 by a bending mirror 2. The laser beam 5 is then split by the apex angle theta of the lens 3 and the condenser lens 4 is brought in line with the central axis of the lens 3 and laser beams 6 split by the lens 3 are condensed by the lens 4. By this method, the irradiation distance interval on the workpiece 13 can be made to the narrow range like 1.5mm, for instance. According to the above-mentioned method, the need for high-degree adjustment work is eliminated and problems of energy loss and generation of a diffraction phenomenon of the laser beam, etc., due to generation of a gap of the lenses can be obviated.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of laser irradiation to a workpiece.

(Jubei's technology) Laser irradiation of a workpiece has excellent characteristics such as a small thermal effect on the workpiece and a short processing time, and is becoming popular in general.

Japanese Patent Publication No. 54-39334 discloses an irradiation method in which laser processing is performed at two locations simultaneously.

As shown in FIG. 4, the laser beam emitted from the laser oscillator 1 is incident on the bar 7 mirror 7, the laser beam transmitted from the bar 7 mirror 7 is received by the bending mirror 2, and the reflected light is collected into the rjS2. As shown in FIG. 5, there is a laser oscillator that condenses the light with the optical lens 4b and also condenses the laser beam reflected from the bar 7 mirror 7 with the first condensing lens 4a to process two points at the same time. A single laser beam emitted from 1 is reflected by a roof-shaped Mitsu-8 combined in a roof shape, and each reflected laser beam is reflected by a bending mirror 2 so that it enters a prism 9, and then enters the prism 9. The direction of the laser beam is changed so that it is incident on a condensing lens 4, and the condensing lens 4 focuses the laser beam on two points.

In addition, as shown in FIG. 7, two fan-shaped partial lenses 11
&, 11b and used as an integrated lens 10 as shown in FIG. 6, it is also possible to irradiate two points with a laser beam at the same time. Partial lens used here
A and 11b are condenser lenses having the same focal length, and are integrated. Further, as shown in FIG. 8, when the partial lenses lla and llb are integrated, the irradiation point spacing g can be changed by setting an angle θ.

(What the invention seeks to solve [ff]) The conventional method of performing laser processing on two places at the same time uses mirrors, half mirrors, prisms, etc., so the structure of the device is complicated, and it is very difficult to position them. In addition, the method of focusing the laser beam using the lens 10 that integrates the two m-shaped partial lenses 11a and Ilb shown in FIGS. Adjusting the angle θ in the m8 diagram in order to control the spacing requires sophisticated adjustment techniques, and energy loss due to the gap between the two lenses that occurs when changing the angle θ, as well as the diffraction phenomenon of the laser beam. There are problems such as occurrence.

The present invention provides a laser irradiation method in which the interval between irradiation points on a workpiece can be easily controlled within a narrower range using one laser oscillator.

(Means for Solving the Problem) The present invention splits a laser beam output from a laser oscillator into two or more parts using a chevron-shaped lens inserted on the way to the workpiece, and focuses the laser beam using a condensing lens. A laser irradiation method for a workpiece, characterized by controlling the interval between irradiation points on the workpiece by controlling the apex angle θ of a mold lens, and a laser beam output from a laser oscillator reaching the workpiece. The beam is divided into two or more parts by a chevron-shaped lens inserted in the middle, and the beam is focused by a two-piece condensing lens, and the distance between the irradiation points on the workpiece is controlled by controlling the distance between the two condensing lenses. This is a method of laser irradiation to a workpiece, which is characterized by a Vt characteristic.

(effect) The operation of the present invention will be described above with reference to the drawings.

tpJ1 diagram shows a method of controlling the interval between irradiation points on the workpiece 13 in laser irradiation using the chevron-shaped lens 3. In this case, the interval between irradiation points on the workpiece 13 is controlled by matching the central axis of the laser beam 5 with the apex angle and central axis of the chevron-shaped lens 7, and by changing the vertex angle θ of the chevron-shaped lens 3. In addition, as shown in Fig. 2, tjIJ1'A optical lens 7:4
a and the central axes of the I'S21 optical lens 4b are aligned,
The first condenser lens shown in FIG. 3 is arranged so that the central axis of the laser beam 5, the apex angle θ and the central axis of the chevron-shaped lens 3, and the central axes of the first and second condenser lenses coincide with each other. By changing the distance 1□ between 4a and the second condensing lens 4b, the workpiece 1
3 to control the irradiation and α spacing g. First condensing lens: 4
When the focal length of g is rl and the focal length of the second condensing lens 4b is f2, the condensing diameters d5, d2, and the second condensing lens 4b are
The following relationship is obtained between the distance l from to the irradiation position and the irradiation point interval g.

dl, d2'' (fl, r2.1□) +3' (fl, [2,1□) g oc ([fl, 1□, θ) As shown above, the chevron lens and condensing lens are fixed lenses. Even if treated as d, by changing only the distance #112 between the lenses,
, %di, Iff, and g can be varied. Incidentally, II is set so that the laser beam divided by the chevron-shaped lens 3 enters the center of the first optical lens 7:4a.

Furthermore, if a polygonal pyramidal lens is used as the chevron-shaped lens, simultaneous irradiation with position control at multiple points becomes possible. For example, if a quadrangular pyramidal lens 12- as shown in FIG. 9 is used,
Simultaneous irradiation is possible with position control at 4 points.

(Example) Using the apparatus shown in FIG. 1, a laser beam 5 is irradiated from a laser oscillator 1, and a chevron-shaped lens 3 is
The central axis of the laser beam 5 is aligned with the central axis of the laser beam 5, and the laser beam 5 is divided at the apex angle θ=177° of the chevron-shaped lens 3.
When the central axis of the condenser lens 4 is aligned with the central axis of the convex lens 3 and the laser beam 6 split by the convex lens 3 is focused by the condenser lens 4 with a focal length f = 50, the processing is performed. The distance between the irradiation points on object 13 could be set to 1.5 mm. In addition, in Fig. 3, a chevron-shaped lens 3 with an apex angle θ = 171° is used, two condensing lenses with a focal length f1 = fz = 50 mm are combined, and the distance between the lenses is set to 20 am.
By changing the distance from 2.5 mm to 301, it was possible to control the irradiation point gap g of the workpiece 13'' from 2.5 mm to 3.5 mm.

(Effects of the Invention) According to the present invention, problems such as energy loss due to the occurrence of a gap in the lens and occurrence of a diffraction phenomenon of a laser beam can be solved without requiring extensive Ii1 alignment techniques.

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing an apparatus for carrying out the present invention, Fig. 2 is a diagram schematically showing an apparatus combining a chevron-shaped lens and two condensing lenses, and Fig. 3 is a diagram showing the optical system of Fig. 2. An enlarged view of the location, Figure rjS4 is a diagram showing the outline of the device that processes two points at the same time using a half mirror, Figure 5 is a diagram showing the outline of the i-position that processes two points simultaneously using a prism, Figure PjIJ6 is the integrated Figure 7 is a plan view of the integrated lens, and Figure 8 is a schematic diagram of irradiation using the integrated lens, in which partial lenses are combined at an angle θ. The figures shown in FIG. 9 are a plan view (FIG. 9(a)) and a side view (FIG. 9(b)) of a quadrangular pyramidal lens. 1... Laser oscillator, 2... Bending mirror,
3... Mountain-shaped lens, 4... Condensing lens, 4a...
tjtJ1 condenser lens, 4b... second condenser lens, 5
．． 6... Laser beam, 7... 8-7 mihu, 8.
... Ridge-shaped mirror, 9... Prism, 10... Integrated lens, 11a. flb...partial lens, 12...square pyramidal lens,
13...Processed product.

Claims (2)

[Claims] (1) The laser beam output from the laser oscillator is divided into two or more by a chevron-shaped lens inserted on the way to the workpiece, and the beam is focused by a condensing lens, and the apex angle θ of the chevron-shaped lens is controlled. A method of laser irradiation to a workpiece, characterized by controlling the interval between irradiation points on the workpiece. (2) The laser beam output from the laser oscillator is split into two or more parts by a chevron-shaped lens inserted on the way to the workpiece, and the beam is focused by a two-piece condensing lens, and the beam is placed between the two condensing lenses. A method for irradiating a workpiece with a laser, characterized by controlling the distance between irradiation points on the workpiece by controlling the distance between the irradiation points on the workpiece.